From: H.J. Lu <hjl.tools@gmail.com>
Date: Thu, 20 Jan 2022 02:09:40 +0000 (-0800)
Subject: fs/binfmt_elf: use PT_LOAD p_align values for static PIE
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9630f0d60fec;p=linux.git

fs/binfmt_elf: use PT_LOAD p_align values for static PIE

Extend commit ce81bb256a22 ("fs/binfmt_elf: use PT_LOAD p_align values
for suitable start address") which fixed PIE binaries built with
-Wl,-z,max-page-size=0x200000, to cover static PIE binaries.  This
fixes:

    https://bugzilla.kernel.org/show_bug.cgi?id=215275

Tested by verifying static PIE binaries with -Wl,-z,max-page-size=0x200000 loading.

Link: https://lkml.kernel.org/r/20211209174052.370537-1-hjl.tools@gmail.com
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Fangrui Song <maskray@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index b9a33cc34d6bf..605017eb9349e 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1116,11 +1116,11 @@ out_free_interp:
 			 * independently randomized mmap region (0 load_bias
 			 * without MAP_FIXED nor MAP_FIXED_NOREPLACE).
 			 */
-			if (interpreter) {
+			alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum);
+			if (alignment > ELF_MIN_ALIGN) {
 				load_bias = ELF_ET_DYN_BASE;
 				if (current->flags & PF_RANDOMIZE)
 					load_bias += arch_mmap_rnd();
-				alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum);
 				if (alignment)
 					load_bias &= ~(alignment - 1);
 				elf_flags |= MAP_FIXED_NOREPLACE;